Building permits, zoning and septic rules in Colorado County, Texas

Colorado County requires a development permit before construction or substantial improvement begins¹. The official form does not identify that approval as a conventional building-code permit, so ask Development & Permitting whether the scope of your project triggers any review beyond addressing and floodplain requirements¹. We could not confirm a separate county building-inspection or certificate-of-occupancy process for residential work in unincorporated Colorado County. Septic installation or repair always requires its own county permit, separate from the development permit⁹. Inside Columbus, municipal rules differ because the city has adopted the 2018 IBC⁴.

Colorado County Development & Permitting issues the required development permit before construction begins and handles 911 addressing and floodplain review¹. The residential development permit costs $30, a commercial development permit costs $350, and a 911 address sign costs $10¹. The application asks whether the property or structure is in a flood-hazard area, and review may require more information or an elevation certificate¹. The Colorado County Permit Office handles OSSF applications, plan review, fees, and final inspections as a separate process⁵. Contact Development & Permitting to confirm the development review for the parcel and proposed structure¹.

Texas does not give Colorado County general zoning authority over unincorporated land, so county zoning does not set minimum lot size, setbacks, lot coverage, building height, or zoning-based restrictions on RVs, tiny homes, manufactured homes, or accessory dwellings there². City limits change the answer: Columbus has a zoning ordinance and uses the 2018 IBC, while Weimar also exercises municipal zoning authority^3,4. Those city rules do not govern unincorporated parcels. Outside municipal limits, a division used primarily for qualifying agricultural, farm, ranch, wildlife-management, or timber-production purposes can be exempt from county plat approval if it does not create streets or other areas for public or lot-owner use; the exemption ends when the qualifying use ends¹⁰.

Colorado County requires the landowner to complete an OSSF permit process for septic construction⁵. The residential fee is $250 and the commercial fee is $350; after payment, a licensed site evaluator, registered sanitarian, or registered engineer must complete the soil survey and site evaluation⁵. Only about 2.9% of county soils lack severe limitations for a conventional drain field, so evaluate the site before choosing a system¹¹. A statewide exemption may apply to one single-family home on at least 10 acres when every system component is at least 100 feet from the property line and all other conditions are met⁶. Otherwise, construction starts only after the Permit to Construct; the installer must request inspection before covering the system, and the final permit follows a discrepancy-free inspection⁵.

Colorado County cannot use general county zoning to prohibit RV occupancy, tiny-home occupancy, or temporary camping on unincorporated land². We could not confirm a separate countywide occupancy rule, so ask Development & Permitting about the specific parcel and proposed setup¹. In a subdivision governed by county development regulations, an occupied structure must use a public sewer or a Colorado County-approved OSSF, and its water may come from an individual supply, an approved community system, or an engineered rainwater system¹⁰. Municipal zoning in Columbus or Weimar can change the land-use answer inside those cities^3,4. A manufactured home also must meet Texas installation standards and cannot be occupied before installation except for viewing on a retailer's lot¹².

1. Confirm whether the parcel is unincorporated or inside Columbus or Weimar, where municipal zoning applies^3,4.
2. Apply for the $30 residential development permit before construction and complete the county's flood-hazard review¹.
3. If the parcel is within the Colorado County Groundwater Conservation District, register a new well before drilling and ask which management zone and operating-permit threshold apply⁸.
4. Apply for the $250 residential OSSF permit and obtain the required professional site evaluation and soil survey⁵.
5. Wait for the OSSF Permit to Construct, then request final inspection before the installer covers the system⁵.
6. For a culvert in a county road right-of-way, apply through the precinct commissioner; the culvert must be at least 20 feet wide⁷.

Check septic suitability, groundwater-district boundaries, flood exposure, road access, and city limits before buying. Only 2.9% of Colorado County soils lack severe limitations for a conventional drain field, making an early site evaluation especially useful¹¹. Within the Colorado County Groundwater Conservation District, every new well must be registered before drilling, even when it may be exempt from an operating permit⁸. Management Zone 1 and Management Zone 2 use different capacity and acreage thresholds, so confirm the parcel's zone with the district before sizing a well⁸. About 97.3% of the county has a slope of 15% or less, but floodplain review still occurs through the development-permit application^1,11. The effective property tax rate is about 1.1%, with a median annual bill near $2,117¹¹.